US Patent 10174595 Perforating tool

A charge tube for use with a perforating tool that includes a tubular member having a first end, a second end, an outer surface, and a passage extending between the first end and the second end, and a receptacle extending through the outer surface of the tubular member for receiving a shaped charge, wherein the tubular member includes a reduced diameter section, and a first expanded diameter section disposed at the first end of the tubular member, the first expanded diameter section having a greater diameter than the reduced diameter section, and wherein the reduced diameter section and the first expanded diameter section of the tubular member are monolithically formed.